The Oxygen Reduction Reaction on Pt: Why Particle Size and Inter-particle Distance Matter

Abstract

Carbon supported Pt based nanoparticles are important electrocatalysts for\nenergy conversion reactions such as the oxygen reduction reaction (ORR). Although\nthis reaction has been extensively studied, the influence of factors such as\nthe particle size and inter-particle distance of the nanoparticle-based or\nnano-sized electrocatalysts on the ORR activity and durability are not yet fully\nunderstood and often intertwined. This lack of understanding is mostly based on\nthe limitation in the synthetic approaches of the electrocatalysts which\nusually do not allow an independent variation of particle size and inter-particle\ndistance. In the presented work, we succeeded to disentangle both factors using\na “colloidal toolbox” approach and have demonstrated an effect of the inter-particle\ndistance on the electronic properties of the nanoparticle via operando electrochemical\nX-ray absorption spectroscopy (XAS).